Trifluoroacetic acid → 1-Phenyl-1,2-dihydro[1,4]oxazino[2,3,4-jk]carbazol-7-ol

HRID 2415807Notes

Reaction equation

HRID 2415807 reaction equation
[C:1]1([CH:7]2[N:21]3[C:22]4[C:14]([C:15]5[C:16](=[O:23])[CH2:17][CH2:18][CH2:19][C:20]=53)=[CH:13][CH:12]=[CH:11][C:10]=4[O:9][CH2:8]2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.FC(F)(F)C(O)=O.[Br-].[Li+].C(=O)([O-])[O-].[Li+].[Li+]>C(OCC)(=O)C.C(#N)C>[C:1]1([CH:7]2[N:21]3[C:22]4[C:14]([C:15]5[C:20]3=[CH:19][CH:18]=[CH:17][C:16]=5[OH:23])=[CH:13][CH:12]=[CH:11][C:10]=4[O:9][CH2:8]2)[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=1

Participants

6

Reactant 4

HCID 6422Trifluoroacetic acidHCID 11125Lithium CarbonateHCID 82050Lithium BromideHCID 121486191-phenyl-1,2,9,10-tetrahydro[1,4]oxazino[2,3,4-jk]carbazol-7(8H)-one

Product 1

HCID 121486261-Phenyl-1,2-dihydro[1,4]oxazino[2,3,4-jk]carbazol-7-olYield 26.4%

Reagents, catalysts & solvents 1

HCID 21930812Acetonitrile ethyl acetateSolvent

Conditions

Temperature
80 °C

Procedure

To 1-phenyl-1,2,9,10-tetrahydro[1,4]oxazino[2,3,4-jk]carbazol-7(8H)-one (4.0 g, 13.19 mmol) in ethyl acetate/acetonitrile (30 mL/15 mL) is added trifluoroacetic acid (2 mL) and anhydrous cupric chloride (3.56 g, 26.4 mmol). The mixture is heated to reflux at 80° C. for 1.5 h. The mixture is concentrated. The residue is dissolved in ethyl acetate (50 mL) and filtered to remove inorganic solids. The filtrates are washed with saturated potassium carbonate solution followed by water, dried over magnesium sulfate and concentrated. The residue is dissolved in DMF (15 ml) to which is added lithium bromide (2.4 g, 27.7 mmol) and lithium carbonate (2.04 g, 27.7 mmol). The mixture is heated at 120° C. for 4.5 h then partitioned between water and CH2Cl2 with the organic layer being washed twice with brine (30 mL). Column chromatography (200 g silica gel) using EtOAc/hexanes (20/80) as eluent gave 1.05 g (26%) of 1-phenyl-1,2-dihydro[1,4]oxazino[2,3,4-jk]carbazol-7-ol.

Workup

  1. temperatureThe mixture is heated
  2. concentrationThe mixture is concentrated
  3. dissolutionThe residue is dissolved in ethyl acetate (50 mL)
  4. filtrationfiltered
  5. customto remove inorganic solids
  6. washThe filtrates are washed with saturated potassium carbonate solution
  7. dry with materialdried over magnesium sulfate
  8. concentrationconcentrated
  9. dissolutionThe residue is dissolved in DMF (15 ml) to which
  10. temperatureThe mixture is heated at 120° C. for 4.5 h
  11. customthen partitioned between water and CH2Cl2 with the organic layer
  12. washbeing washed twice with brine (30 mL)

Sources & evidence

ORD record
ord-3a6325d9ab15466ea0af800533634c32
Source dataset
uspto-grants-2004_11
Patent number
US06821970B2

Reaction notes

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